KR20000044352A - Routing method for satisfying service quality in private asynchronous transmit mode exchange network - Google Patents

Abstract

PURPOSE: A routing method for satisfying service quality in a private asynchronous transmit mode exchange network, is provided to reduce a call setup time in a precomputing path select and an optimal path satisfied the service quality of an on-demand type, when supporting a service about a multimedia traffic in an exchange period. CONSTITUTION: A routing method for satisfying service quality in a private asynchronous transmit mode exchange network, comprises the steps of: deciding a service list, if a user requests for a service; setting up a service quality parameter for selecting a first path according to the decided list; executing a routing by an on-demand type according to the service parameter; setting up the service quality parameter for selecting a second path; and executing the routing by the on-demand type.

Description

Routing Method for Satisfying Quality of Service in Private Asynchronous Transfer Mode Switched Networks

The present invention relates to a private asynchronous transfer mode (hereinafter referred to as ATM) switching network, and more particularly to a routing method for satisfying the quality of service.

In general, a private network network interface (hereinafter referred to as a PNNI) is a standard standard established for signaling and routing of a network-network between ATM exchangers in an ATM forum. PNNI uses the source routing method as a routing method, which establishes the route from the node where the connection request originated from this node to the destination address based on the information about the network topology synchronized to all nodes in the network.

In the conventional routing method, an ingress ATM switch calculates a path to an egress ATM switch, and stores a list of nodes passed through the signaling process as a designated transit list in a signaling process. The structure of supporting the quality of service in the conventional routing is as shown in FIG. First, each node (A1 ~ A4) basically supports the list of supported services such as CBR, rtVBR, nrtVBR, ABR, UBR, administrative weight, cell transfer delay, and cell loss ratio. Information about the resource, etc., should be distributed to neighboring nodes. Based on this information, the entrance node applies the generic call admission control algorithm to route the link that satisfies the quality of service.

However, the problems encountered in applying the prior art to the private ATM PNNI can be seen in two aspects: call setup time and quality of service requirements. In the data-oriented network structure such as the existing LAN, the precomputed method is mainly used when setting the path. This method is a path selection method in which the node satisfies the requirements for the service by confining the path information calculated in advance before receiving the call establishment message. This route selection method has an advantage that the call setup time can be faster because it uses pre-computed information. However, since the path selection method is made from a static point of view rather than a dynamic point of view, there is a performance problem in establishing a path that satisfies an optimal quality of service in a network structure that must accommodate multimedia such as ATM.

On the other hand, there is an on demand path selection method that selects a path when a call establishment message is received between nodes. In this method, it is possible to set the optimal route that reflects the service quality of the service list requested by the user. However, since the call establishment time must find a path that satisfies the required quality of service, the call setup time is increased, which causes a problem of an increase in delay when a real-time service needs to be provided.

Accordingly, an object of the present invention is to provide a routing method that satisfies the quality of service requirements according to the characteristics of each service in a private ATM switching network.

Another object of the present invention is to provide a routing method for satisfying call setup time and quality of service in a private ATM switching network.

In order to achieve the above object, the present invention analyzes the quality of service requirements according to the characteristics of each service in a private ATM switching network, and based on the analyzed parameters, firstly applies the pre-calculated route setting based on the analyzed parameters. By applying the on-demand path selection method, it is possible to determine a path that satisfies call setup time and quality of service requirements.

1 is a diagram illustrating a conventional routing structure.

2 illustrates a routing structure in accordance with the present invention.

3 is a diagram illustrating a routing process according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In the present invention, first, a service quality parameter is required for a service requested by a user. The quality of service parameter conditions required for each service are shown in Table 1.

Service parameter rtVBR nrtVBR CBR ABR UBR CDV ○ ○ maxCTD ○ ○ ○ CLR0 ○ ○ ○ CLR0 + 1 ○ ○ ○ AVCR ○ ○ ○ ○ maxCR OPTION OPTION ○ ○ CRM OPTION OPTION ○ ○ ○ VF ○ ○

As shown in Table 1, it can be seen that there is a difference in service quality required according to service characteristics. Therefore, the route selection method is classified as follows according to the service requested by the user.

1) CBR / rtVBR / nrtVBR Service

CBR / rtVBR / nrtVBR service is delay sensitive because it supports real-time service. Therefore, in order to minimize the effect on delay, the path is first set in a precomputed manner for the delay constraint, and then on demand for other quality of service requirements such as bandwidth among the selected paths.

2) UBR / ABR Service

The UBR / ABR service first performs a precomputation method for bandwidth resources, and then selects a path on demand based on the delay among the paths formed based on this path setting to satisfy the service quality required by the user. Take

As such, the selection criteria of the service quality parameter for each service list to which the route selection method is applied are as shown in Table 2.

Type of service Step 1 (line calculation method) Tier 2 (on demand) CBR / rtVBR / nrtVBR delay Bandwidth ABR / UBR Bandwidth Delay etc

2 shows a routing structure according to the quality of service according to the present invention.

2, the service list determining unit 210 determines a list of services set by a user and provides the result to the service quality parameter setting unit 220. Then, the service quality parameter setting unit 220 sets a parameter according to the set list of services. At this time, the pre-calculation routing setting unit 230 applies a delay as a parameter for selecting the first path when the set service is a CBR / VBR service. In addition, the pre-calculation routing setting unit 230 applies the bandwidth as a parameter for selecting the first path when the set service is a UBR / ABR service. The on-demand routing setting unit 240 selects a path that satisfies a condition for satisfying a requirement of a quality of service parameter (eg, bandwidth) set by a user when the set service is a CBR / VBR service. In addition, the on-demand routing setting unit 240 selects a path in an on-demand manner with respect to a delay as a parameter requested by a user when the set service is a UBR / ABR service.

3 shows a routing process for satisfying a quality of service in a private ATM switching network according to an embodiment of the present invention.

A routing method for satisfying a quality of service in a private ATM switching network according to the present invention will be described with reference to FIGS. 2 and 3. If there is a service request from the user in operation 310, the service list determining unit 210 determines a category of services set by the user in operation 320. In step 330, the service quality parameter setting unit 220 sets a parameter of the quality of service according to the list of services determined by the service list determining unit 210. If the determined list of services is a CBR / VBR service, in step 331, the service quality parameter setting unit 220 applies a parameter required for the first path selection as a delay. In operation 332, the line calculation routing setting unit 230 sets a path in a line calculation manner, and in operation 333, the quality of service parameter setting unit 220 applies a parameter required for selecting a second path as a bandwidth. Let's do it. In step 334, the on demand routing setting unit 240 sets a path in an on demand manner according to the bandwidth.

Meanwhile, when the determined list of services is a UBR / ABR service, in step 341, the service quality parameter setting unit 220 applies a parameter required for the first path selection as a bandwidth. In step 342, the pre-calculation routing setting unit 230 sets a path by a pre-calculation method according to bandwidth, and in step 343, the service quality parameter setting unit 220 sets a parameter necessary for selecting a second path. Apply with delay. In step 344, the on demand routing setting unit 240 sets a path in an on demand manner according to a delay.

As described above, the present invention can reduce call setup time in selecting an optimal path and a pre-calculated path that satisfy the quality of service in an on-demand scheme when supporting a service for multimedia traffic during a switching period in a private ATM switching network.

Accordingly, the present invention has the advantage that can be effectively routed for real-time services such as video and voice as well as data services in a private ATM switching network.

Claims (3)

A routing method for satisfying a quality of service in a private ATM switching network, When the user requests a service, the process of determining the list of services, Setting a quality of service parameter for selecting a first route according to the determined list of services; Performing routing based on a pre-calculation method according to a quality of service parameter for selecting the first route; Setting a quality of service parameter for selecting a second route according to the determined list of services; Routing according to the on-demand method according to the quality of service parameter for selecting the second path routing method for satisfying the quality of service in a private ATM switching network. The method of claim 1, If it is determined that the list of services is a CBR / rtVBR / nrtVBR service, the quality of service for selecting a second path after performing routing based on a pre-calculation method by applying a quality of service parameter for selecting the first path as a delay. A routing method that satisfies the quality of service in a private ATM switching network, by applying a parameter as a bandwidth to perform routing on demand. The method of claim 1, If it is determined that the list of services is a UBR / ARB service, the service quality parameter for selecting the first path is applied as a bandwidth to perform routing by the pre-calculation method, and then the service quality parameter for selecting the second path is selected. A routing method that satisfies the quality of service in a private ATM switching network, characterized in that routing is performed on demand by applying a delay.